Synthetic amorphous silica manufactured by flame hydrolysis or by precipitation in an aqueous solution is characterized by its amorphous structure. The determination method used on typical samples is enrichment of the crystalline fraction followed by X-ray Diff raction. The detection limit of this method is less than 0.05 % by weight. Under consideration of this detection limit Evonik Industries AG silica are considered to be amorphous.
Toxicology & Ecotoxicology
Synthetic amorphous silica is an inorganic water insoluble substance. For this reason its bioavailability is very low for aquatic organisms. In acute tests according to OECD test guidelines with fish and daphnia nominal concentrations of 1000 and 10 000 mg / l respectively showed no effects. Based on the physicalchemical and acute toxicological data no chronic effects and no bioaccumulation are expected in aquatic organisms. The general guidelines for the examination of the biodegradability of substances (OECD-, EEC-guidelines) can be used only for organic substances. Synthetic amorphous silica is an inert inorganic substance and will not biodegraded by microorganisms. The German commission for the evaluation of water polluting substances has classified synthetic amorphous silica as a not water endangering substance (KBwS-No: 849).
Silica is also included in the OSPAR list of substances / preparations used and discharged offshore which are considered to Pose Little or No Risk to the Environment (PLONOR).
Information on Handling
Air removal pumps are recommended for facilities that process Evonik Specialty Silica in powder form. In conditions where Evonik Specialty Silica concentrations exceed the MAK (maximum work place exposure) value of 4 mg / m3 (inhalable fraction), a dust mask (P2 Particle Filter Class) must be worn. Electrostatic charges may form when handling Evonik Specialty Silica, so that the facilities used must be adequately grounded. To avoid the feeling of dryness that results from contact with bare skin, Evonik Specialty Silica should be washed off using water and exposed skin should be treated with moisturizing cream. Spilt product should be collected with a minimum of dust build-up and collected in adequately sealable containers. Evonik Specialty Silica can be disposed of as per recommendations in the European Waste Type Catalog, which is set up by industry.
Based on currently applicable standards of Chemical Substance Legislation, the Hazardous Substance Advisory and Transportation Regulations, hydrophilic Evonik Industries AG Specialty Silica products are not classified as dangerous substances or goods.
Safety Data Sheets
You can obtain further information on Product Safety or our Safety Data Sheets from:
Product Safety Department
Tel. +49 6181 59-4787
Fax +49 6181 59-4205